Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds the 50-block cap and the no-key/no-credits condition, which is useful, but 'Existing source and input limits apply' is unquantified boilerplate rather than real behavioral disclosure.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The core purpose is correctly front-loaded in the first sentence, but the next two sentences are repetitive marketing filler ('FREE during validation. No key, credits, wallet or preparation needed') that consume space without adding actionable information.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

An output schema exists, so return values need not be explained. However, for a nested-object input with 0% schema description coverage, the missing explanation of the html parameter and the vague 'limits apply' clause leave gaps an agent must guess at.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 0% and the single parameter is a nested object (input.html, maxLength 100000). The description's only parameter guidance, 'Supply your task in input,' does not match the schema, which requires input.html as a string, and no hint about the HTML string or its size cap is given beyond the vague limits note.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb (Parse) and resource (JSON-LD blocks from HTML) with a concrete limit of 50 blocks, which clearly separates it from siblings like html_metadata or html_headings. It does not explicitly name a sibling alternative, so it falls short of the 5 tier.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

There is no explicit when-to-use or when-not-to-use guidance, and no alternatives among the many html_* and web_* siblings are named. The 'FREE during validation' remark hints at a trial context but gives no routing instruction for the agent.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.